Method for producing phosphonium salts

A process for preparing a quaternary phosphonium salt comprising reacting a trialkyl-, trialkenyl- or triarylphosphine with an optionally substituted monounsaturated or polyunsaturated aliphatic, cycloaliphatic aromatic-aliphatic alcohol having from 3 to 25 carbon atoms or its carboxylic acid esters or ethers in the presence of an acid, or by reacting a trialkyl, trialkenyl- or triarylphosphine with an optionally substituted aliphatic, cycloaliphatic or aromatic-aliphatic halide having from 3 to 25 carbon atoms, wherein the reaction is conducted in a ternary solvent mixture, and

• wherein the quaternary phosphonium salt is of general formula I
• [R1—P(R2)3]+X− (I),
• where
• R1 is an optionally substituted monounsaturated or polyunsaturated aliphatic, cycloaliphatic or aromatic-aliphatic group having from 3 to 25 carbon atoms,
• R2 is an alkyl, alkenyl or aryl group having from 1 to 9 carbon atoms,
• X is an anion equivalent of an organic or inorganic acid and
• the trialkyl-, trialkenyl- or triarylphosphine is of general formula II
• P(R2)3 (II),
• where R2 has the meaning given above, and the triakyl-, trialkenyl-, or triarylphosphine is reacted with a monounsaturated or polyunsaturated electophile of the general formula III or IV,
• where R1 has the meaning given above, and
• R1′ is an optionally substituted, aliphatic, cycloaliphatic or aromatic-aliphatic hydrocarbon group having from 1 to 21 carbon atoms,
• Y is OH, Cl, Br, O(CO)R3 or OR3 and R3 is an aliphatic hydrocarbon group having from 1 to 6 carbon atoms, and
• R4 is H or CH3 and, when an electrophile of the general formula IV is reacted,
• R1 in formula I is a structural element of the general formula V
• where R1′ and R4 have the meanings given above.